Roadway and method of making the same



March 19, 1929. 5, 5, SADTLER 1,706,077

ROADWAY AND METHOD OF MAKING THE SAME Filed MaICh 6, 1926 WIT/V555 @patented 19, 1929.

UNITED STATES PATENT OFFICE.

SAMUEL S. SADTLER, OF SPRINGFIELD TOWNSHIP, MONTGOMERY COUNTY, PENNSYL- VANIA, ASSIGNOR TO AMIESITE ASPHALT COMPANY OF AMERICA, F CAMJDEN,

NEW JERSEY, A CORPORATION OF NEW JERSEY.

ROADWAY A N D METHOD OF MAKIN G THE'SAME.

Application filed March 6, 1926. Serial No. 92,954.

My invention`relates to roadways for vehicular travel and to the method of ymaking such roadways,particularly in those localities which may be remote from a source of stone suitable for the foundation or in a locality where an expensive stone or cement foundation is not 'warranted by the amount and kind of traffic. which the road is designed to support and bear, for my invention has, among 1H its objects, the' utilization of the very materials that are removed from the earth to provide a space for the foundation of the f roadway, as the foundation material upon which is/laid a suitable surfacing material.-

lo A further object of my invention is to so treat the ordinary earth and soils of the locality in which the road is to be laid as to make therefrom a foundation which will be a suitable and adequate substitute for a cement or rock foundation where, for good and Sullicient reasons, the expense of a crushed rock or cement foundation is not warranted. n J A further object of my invention is to v,make .a good serviceable, highly satisfactory roadway which will support, without breaking down, comparatively heavy vehicular travel, at an exceedingly low cost of road material, Jfreight and labor.

Other objects of my invention will appear in the specification and claimsibeloyv.' In the drawings forming a part of this specication and inwhich'the same reference characters are employed throughout the various views to designate the same parts,

' Fig. l shows a section of land in which my improved road is-to be made, the dotted line being an indication of the depth or level to which the earth is tobe excavated andthe part enclosed by the dotted line indicates the earth to be removed. o i

Fig. 2 shows the roadway excavated and the earth removed from curb to curb to form the roadbed. v

Fi 3 shows the manner in which drains may e further excavated on opposite sides of the road and adjacent the curbs where draining is necessary or desirable. I

Fig. 4`shows the foundation filled in to the excavationshown in Fig. 3 and a surfacing applied to the top thereof. y

Fig 5..is a. 4view similar to Fig. 4 but` in which is substituted a heavier surfacing than o that shown in Fig. 4. n

Fig. 6 is a `cross-sectional view of a roadway in which the foundation is in place as in the I5 previously illnstratedforms but in which an expanded metal or chicken wire'is rlaid over the entire surface of the foundation.

Fig. 7 shows the next step in the completion of the road illustrated in Fig. 6 wherein 60 the chicken wire is covered with a layer of asphaltic material and is rolled to the foundat1on.

Fig. 8 shows the last step in the road illustrated in Figs. 6 and 7 wherein a surfac- 35 ing of asphaltic paving, such as amiesite, is laid over the asphaltum coated chicken wire and united thereto and to the foundation by the intermediate layer of paving material with the metallic chicken wire or expanded metal incorporated therein.

The thickness of the reticular metal is, of course, greatly exaggerated in Figs. 6, 7 and 8 for the sake of clearness.

In carrying out my invention, I rst excavate the earth 1 to form a shallow trench 2 to the full width of the road to be made, the excavation being, for example, to a depth of from 6 to 8 inches. Where, from the character of the land there is a liability of the presence of a good deal of water, I dig trenches, 3, 3 in the bottom of the excavation 2 along the sides thereof and next to the curb 4 to form side drains, as clearly shown in Fig. 2.

I then take the soil that has been removed from the roadway and heat it in any suitable manner, to a temperature of 200 C. to drive olf a substantial amount of the water of the clay and other hydrousmaterials in the soil, Afor when the water of the clay and other hydrous .mineral materials in the earth is so driven olf or expelled, the change effected in the clayey materials so treated is practically a permanent one. The more or less anhydorus clay or similar materials thus produced does not again become hydrous upon exposure i to water. They no longer become plastic when mixed with water, but water runs through them almost as freely as it does nthrough a stone foundation.

The excavated soil may be heated to a temperatlire of substantially 200 C. by employing a revolving patch heater, using a blast of burning oil. These patch heaters are of wellknown construction and need no further detailed description. However, the earth may be heated in any other convenient manner ed earthy material.

to expel the water contained therein, and to there y impart to the clay water resisting properties.J

After having been so heated, the earth is spread upon the roadbed 2 and may be comla surface finish so as to make it better wit-hstand the wear of traflic, to make it more readily shed or resist water, and to prevent the formation of dust.

I may, therefore, sprinkle upon the lfoundation, a'water-resisting or repellent substance, such as zinc stearate, a very small quantity of which willgreatly increase the water repelling properties of the heat-treat- Such metallic salts or fatty acids, keep the upperY layers of dried treated soil free of water and non-/plastic,`.

they tend to prevent the absorption of water bythe roadbed/and when the surface is laid therein they contribute to a better nbond between the foundation and the surfacing.

To further insure the prevention.- of the foundation 5from becoming plastic and soluble, I may mix with the heat-treated soil, orJ I maytreat the top surface of the foundation 5 afterit has been put in place, with a small amount of slaked lime (either hydrated lime or air slaked lime) or with carbonateof lime.

The surfacing of thefoundation 5 thus formedmay be effected in avariety of ways dependent, to a great extent, upon the nature of the traffic to which the road will be subjected in the,future. For light traffic, the

n surface of the foundation 5 inay be provided .by merely oilin tion 5. The

formed and compacted, a road'oil may be ap-I the surface ofthe foundaoundation 5 having -been plliled tothe surface thereof. In Fig. 4, the 'shed road is shown'as bein provided with an oil surfacing 6. The roa loil penetrates' into the foundation and covers the surface particles with oil, so applied, thus forming a water-resisting, dust preventing surface.

For heavier-traiic thereover, the surface may be coated with a heavier bituminous course or layer 7, by laying liquid asphalt or a thin coal tar pitch thereon and sprinkling the same with small fstones, and rolling the same into the surface of the foundation, or the surface course 7, may be of the well known amiesite construction.

yIn the preferred form ofv my invention and in which the surface of the road is to be a permanent one and capable of withstandingv Iheavy traffic, 'I first place and form the foundation 5 of water resisting earths obtained, as

above described, by heating the soil excavated in' preparing the roadbed, and has been above 'described in connection with Fig. 4, and then I may place thereon sheets or strips 8 of expanded or woven metal. Chicken wire of about one inch mesh is very well adapted for the purposes of my invention when the broken or screened stone of the aggregate ispof a size to pass through a 1% inch mesh screen. But the sizeof the'mesh or foraminous or reticular metal would vary somewhat' with the sizes of the stones used in the aggregate.

The expanded or woven metal 8 is preferably galvanized to resist oxidation of the metal and so galvanized it would last for' some time even/if not subjected to further treatment, but in practice I prefer to coat the same'thoroughly Iwith asphalt, which is a water resistant, and will preservevthe iron from rusting for axvery long period of time.

' The asphaltum covered or coated, reticu- 'Y lated metal is laid on` the foundation 5 over the entire roadway and may be rolled into the-foundation or left free between the foundation 5 and the top surfacingto be placed thereon. I prefer to lay the sheets or strips 8.on the roadway either coated with asphal- `tum or merely galvanized and' to roll it into the surface of the foundation 5 afterthe surface has been sprinkled with a thin asphaltum composition 9 for in that wa I may finally bind the .metal fabric 8 to oth the upper and lower courses or layers of the road.

Over the expanded metal or chicken wire 8 so placed. coated and rolled into the foundation, I provide the layer 7 or .surfacing of several inches of asphaltic paving material, such as amiesite or screened broken stone so -mixed with asphalt that every piece of the stone is completely coated with asphalt. This surfacing 7 is spreadA over the surface 9 cold and is rolled orv tamped so thatl the fabricated metal -8 is united to the surface 7 and securelyvunites `the foundation course 5 with the surfacing cou-rse or layer 7. Av

layer of sand 10 may be sprinkled over the upperv cou-rse 7 and rolled into the upper course. I may sprinkle the surface of the upper course before or after the above rolling or compressing, with a hydrated lime and/or with carbonate of lime, and/orwith stearate of zinc to harden the 'asphalt and increase the 'water resisting properties of the road.-

The expanded metalor chicken wire fabric', i

serves to lock, bind or hold together the two main layers or strata 5 and7 of the road, but 1t alsoacts'very effectivelyto; distribute over a greater area or surface, the load passing over the road. The amiesite paving or a cold asphaltic bble, or rock pavement is not a r1g1d The pieces of rock are heldin place bythe,-jasphaltic compostion but .13 i

` lar traffic.

ent of the United States is:

The heat treated earth foundation 5 acts substantially the same as a rock foundation..

It permits any water which may be under the waterproof asphaltic surfacing to work its way out into the drain 3, and the drains 3 generally collect and allow any water which would otherwise enter "under the vsurfacing from the earth at the sides of the roadway to seep or drain away. The water repellent materlals, such as stearate of zinc, also check and to a great extent prevent water from entering the foundation course from the drains 3. y f

The lime or carbonate of lime, which may be added to the heat-treated earth also improves the bond between the courses of my improved roadway by its vhardening or toughening action on the asphaltic materials.

vIt is to be clearly understood that the heating of the clayey earth to a temperature of substantially 200 C. is not -merely for the purpose of drying or driving of the free water which may be mechanically mixed with the clay, but also for expelling water which is chemically u'nited with and forms a part of the hydrousfclay. When so heated properties of the clay are changed and the clay is rendered anhydrous 0r anhydrous in part, i. e., some of the water combined with the clayY is expelled, and this change is substantially permanent. The clay does not go back to a hydrous condition onl exposure to moisture, but remains water repellent and in this con` dition is suitable as `thehard material content of foundation material.

Having thus described my invention, what I claim'and desire to protect by Letters Pat;

l. A roadway comprising a compact foundation course consisting of water-repellent clayey earth having intermixed therewith a relatively small quantity of stearate of zinc and a surface course of asphaltic paving material which does not require heating to belaid.

2. A roadway com rising a foundation course consisting of su}bstantially` anhydrous clayey earth having intermixed therewith lime and stearate of zinc, anda surfacing course of asphaltic material. y

3. A roadway comprising a foundation layer or course consisting of 'dry clayey soil which does not substantially absorb water, a yielding surface layer of asphaltic composition, and a reticular sheet of metal coated with asphalt between said surface layer and said foundation and operative to .bind the surface layer to said foundation and to distribute the -load paing over said roadway over a relatively large area of said foundation.

4. A roadway comprising a foundation course consisting of the dry clayey earth excavated from the road to make the bed and which is substantially non-absorbent of water, a sheet of reticulate metal coated with asphalt and embedded in the yielding surface of said foundation course and a surface of asphaltic composition capable of being laid cold and containing aggregate, also embedded in the surface of said foundation and extending through the interstices of Said sheet metal.

55A roadway comprising a foundationl course consisting of water-repellent clayey earth which will not become plastic when mixed with water and intermixed with a small quantity of stearate of zinc, a yielding surface course ofgasphaltic paving material capable of being laid cold, and a reticular sheet of metal binding said surface course to said foundation course and operative to distribute the load of trallic on said roadway over a relatively large area of said foundation.

6. The method of constructing a roadway :in claye soil which consists in excavating and leve 'ng the soil to form a roadbed, heatproviding said foundation course with a bituminous wearing surface.

7. The method of constructing a roadway in clayey soilwhich "consists in excavating and leveling the soil to form a roadbed, heating the soil removed in making the roadbed to a relatively hi h temperature to render the same substantia y anhydrous, placing a compacted course of said substantially anhydrous soi-l pn said roadbed to form the foundation course or layer, and providing said foundation course with a bituminous surface, placing on said foundation a retieular sheet of metal, coating said metal sheet with asphalt,

fac'e layer of bituminous material.

8. The method of forming a roadway ,in clayey'soil which consists in providing a roadbed, heating the soil removed in making "said roadbed to a temperature of substantially 200 C., placinga compacted course of said soil, after it has been so heated, on said roadbed to form the foundation course, sprinkling asphalt overthe surface of said foundation course, placing a reticular sheet of metal over the entire surface of said foundation course, rolling said reticular sheet into Aand laying on said metal sheet a yielding sur- I the surface of said foundation course and then placing upon said reticular sheet a yielding surface course of bituminous material.

9. The method of forming a roadway in f clayey soil which consists in providing a lime over said surface of the layer of bituminous material.

10. The method of constructing a roadway in clayey soil which consists in excavating the soil to form a shallow trench for the full width of the road, heating the soil so removed i, to a ltemperature of substantially 200 C.,

adding to the soil, after it has been so heated,

stearate of zinc and hydrated'lime forming a compacted foundation course in said trench of said anhydrous soil, placing on said foundation course a yielding surfacing of bituminous composition. I

11. The method of making a road in clayey v soil which consists of heating the earth removed in making the roadbed to a high temperature to change the clay andsimilar min- -erals therein, so that they will not become plastic in the presence of water, placing on the roadbed a compact foundation course of 'said earth, after it has been so heated, scattering over the'foundation' so placed a small amount of water repellent and asphalt hardening materials, applying -to the surface ofy --said foundation a yielding .layer of bituminous material containing an aggregate and to the top surface of said upper bituminous course a layer of sand. y

12. The method of making a road in cla ey soil which consists in digging a sha1' ow trench in the earth to the 'depth of from six to eight inches and for the full width of the road to form a roadbed, digging deeper trenches at the sides of the roadbedadjacent the curb to forni drains,- heating the soil excavated in making the `roadb'ed to substantially 200 C., placing on the roadbed a compact foundation course consistingof said soil, after it has been so heated, said course havin a slightly crowned upper surface extendlng over the full width of the roadbed and filling said side drains, adding to the soil so placed relatively small quantities of hydrated lime and Steai rate of zinc, placingxon the surface of said foundaton course so formed a-yielding sur- ,i

face layer of asphalt, sprinkling aggregate on the asphalt surface of said foundatlon and compacting said asphalt and aggregate by rolling.'

13. A roadway comprising a foundation course of clayey soilwhich is non-plastic in the presence o f water, a yielding wearing surf face course of bituminousmaterial, and a sheet of reticular metal, protected by an asphalt coating, lying between said course, and uniting said courses, and operative 'to distributc the load imposed on the surface course,l

over a relatively large area of said foundation, and to prev-ent said Wearing course from spreading under the vehicular traffic to which the roadway is subjected. j

14. roadway comprising a foundation course of clayey soil and containing a small quantity of water repellent materials, a yielding Wearing surface course of bituminous material, and a sheet of reticular metal, protected by an asphaltcoating lying between said courses, uniting said courses and-operative to distribute the load imposed on the surface course, over a relatively large area of said foundat'on course, and to prevent said wearing cour e from spreading substantially under the vehicular trafic to which the roadway is subjected. l

In witness whereof, I have hereunto set my hand thisfourth day of Marcl1,-1926.

SAMUEL s. SADTLER. 

